German Chancellor Angela Merkel has called on Cameron to "clarify the substance" of his demands for a reformed EUGetty

Prime Minister David Cameron will outline the UK's EU membership renegotiation demands in early November. He made the announcement as he arrived at a summit for EU leaders in Brussels amid mounting frustration from the bloc that talks would continue to stall unless Downing Street published its proposals.

"The pace will now quicken and I'll be again setting out the four vital areas where we need change, laying down what those changes will be at the start of November," Cameron said. German Chancellor Angela Merkel and EU Parliament president Martin Schulz had previously called on Cameron to clarify exactly what he wanted. Cameron said that the process will be accelerated before the next EU summit is due to take place in December.

"I'm confident we can get a good deal for Britain, fix those things that need to be fixed and I'm confident that this process is well underway and making good progress," the prime minister said. European Council president, Donald Tusk welcomed the announcement and said that real negotiations can then get underway.

Cameron has pledged to hold a referendum on the country's membership of the EU by the end of 2017. He has also said that he wants the country to stay in the union on revised conditions. European Commission president Jean-Claude Juncker said that little headway has been made so far. "I can't say that huge progress has been achieved. I can't say that nothing has been achieved. But to tango it takes two," Juncker said. "And so we have to dance and our British friends have to dance."

Cameron's key areas of reform are thought to include: exemption from ever-closer ties, limits to welfare entitlement for EU migrants and safeguards for countries outside the currency union. Merkel said that Berlin would work constructively with the UK, but she added: "It goes without saying that there are things that are non-negotiable".